Self regulating heating system and method for a pool, such as a swimming pool

ABSTRACT

A self regulating system and method for heating a swimming pool, using solar energy. There is a cover member which is placed over the surface of the swimming pool and water from the swimming pool is pumped cyclically through flow paths in the cover section. Solar energy directed to the top surface of the cover section heats the water that flows through the cover section. There is a solar power pumping and control system by which solar energy is utilized to supply electrical energy to a battery and also to a motor of a pump. A control section causes the cyclical operation of the pump so that the pumping cycles are related to the intensity of the solar energy which is being transmitted to the system at that time.

RELATED APPLICATIONS

This application claims priority benefit of U.S. Ser. No. 60/616,506,filed Oct. 5, 2004.

BACKGROUND OF THE INVENTION

a) Field of the Invention

The present invention relates to the heating of a body of water, such asa swimming pool, and more specifically relates to a system and method bywhich the system and method is self regulating so that it can optimizeits operation relative to the solar energy which is available, withouthuman intervention.

b) Background Art

Pool heaters have been in use for many years. One type of pool heater iscomprised of an electrical heater unit that heats the water utilizingconventional power. A second type of pool heater is comprised of apassive cover that allows solar energy to enter the pool but retains thesolar energy within the pool. Yet another type of pool heater iscomprised of a solar heater unit that is positioned away from the pool(e.g. on the roof of a house) wherein water is pumped to the solarheater and then returned.

There are also a number of systems for heating the water in a pool usingsolar energy where a cover with flow paths is placed on the top surfaceof the pool. Then water from the pool is circulated through this coverso that it is heated by solar energy and returned to the pool.

There are also systems where solar energy is used to energize a pump byusing a photovoltaic cell to derive electrical energy from the solarenergy to drive the pump.

The embodiments of the present invention are directed toward providing asystem and method of heating a pool such as a swimming pool where thesystem and method can utilize the solar energy efficiently and also sothat the system is self regulating so that it does not require humanattention and/or intervention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of an embodiment of the invention, showing thecover section in plan view, and also showing the power and pumpingsection;

FIG. 2 is a side elevational view, partly in section, showing a swimmingpool with the cover section of the embodiment located in its operatingposition on the surface of the pool and also showing the power andpumping section;

FIG. 3 is an isometric view of a panel of the cover section;

FIG. 4 is a cross sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is a top plan view looking down on the panel but not showing itstop cover sheet;

FIG. 6 is a schematic view of a first embodiment of a power and pumpingsection;

FIG. 7 is a schematic view similar to FIG. 6 showing another embodimentof the power and pumping section;

FIG. 8 is an isometric view of a support and power unit to containcertain components and also to provide various angular orientations of asolar power section;

FIG. 9 is a view similar to FIG. 8, but showing two support members ofFIG. 8 separated from one another;

FIG. 10A is a semi schematic end view of the support and power unit ofFIG. 8, with various sides and angles of the surfaces being illustratedand given designations for purposes of explanation;

FIGS. 10B-10E are simplified views somewhat similar to FIG. 10A, showingvarious arrangements to provide different angular orientations for thesolar power section;

FIGS. 11, 12, 13, 14 and 15 are side views, partly in section showingvarious fluid connections between the panels of the cover section;

FIG. 16 is a side elevational view, partly in section, showing a methodby which the cover section could be removed from, or moved onto thesurface of the swimming pool;

FIG. 17 is a side elevational view showing the panels of the coversection stacked in a stowed configuration.

FIG. 18 is a top plan view of a panel of a fourth embodiment, with thecover sheet removed for purposes of illustration;

FIG. 19 is a sectional view taken along line 19 of FIG. 18;

FIG. 20 is a side view of an inlet end portion of a main feed conduit ofthe fourth embodiment; and

FIG. 21 is a sectional view of one of the outlets in the panel.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

It is believed that a clearer understanding of the embodiments of thepresent invention will be obtained by presenting initially a briefdescription of the main components of the first embodiment of theinvention and then describing the basic operation of this firstembodiment. After that there will be a more detailed description of thevarious components, as well as a description of other embodiments and/ormodifications.

In describing generally the first embodiment, reference will first bemade to FIGS. 1-5. With reference to FIG. 2 there is a swimming pool 10which for ease of presentation in the drawings is simply shown as twowall portions 12 of a surrounding structure 13 of the pool 10. Thestructure of the pool provides a pool region indicated at 14 which isshown as containing water 16 having an upper water surface 18. Thesystem 20 of this first embodiment of the present invention comprisestwo main components. First, there is a cover section 22 which ispositioned at the surface 18 of the water 16, and this provides both aninsulating and heating function for the water 16 in the pool. Then thereis a power and pumping section 24 which circulates water through thecover section 22 in a manner to cause this water to be heated.

We will first turn our attention to the cover section 22. This coversection 22 comprises a cover structure 26 which in this embodimentcomprises a plurality of rectangular panels 28 which extend oversubstantially all of the water surface 18, or at least a substantialportion thereof. These panels 28 are placed with their adjacent sideedges spaced a short distance from one another, and these are connectedto one another by sheets 30 and/or straps 31. Also, there are tubeconnections 32 between adjacent side edges 36 of the panels 28 to enablewater to flow through the panels 28. At the left hand of the coverstructure 26 there is a water inlet 33 to direct water into the leftpanel 28 to flow through the panels 28. There is an outlet 34 at theother end of the cover structure 26. Quick disconnect couplings 35 areprovided at the water inlet and outlet 33 and 34.

The straps 31 and the disconnect couplings 35 make the deployment andretrieval of the cover section 32 easier. The straps 31 span a pair ofadjacent panels 28, with the straps attached at opposite side portionsof adjacent panels, but not at points in between. The straps make itpossible to lift a pair of cover sections at a time out of the water.

With reference to FIGS. 4 and 5, each panel 28 is made of a rectangularbase plate 38 which is made of a buoyant and heat insulating material,such as, for example, a closed cell foam or a thermoplastic foam with noor low absorption. A network of flow paths 40 are provided in the upperportion of each plate 30, with these paths 40 being in a form of grooves40 which are shown as having a “V” shaped cross section, but these couldbe square, rounded, etc. Also, the side portions of the two panels 28are formed with side openings 41 to connect with the tube connections 32and enable the water to flow from the paths 40 in one of the panels 28to an adjacent panel 28. At the upper surface of each base plate 38there is a cover sheet 42 that is bonded to the upper surface of thepanel 28 to seal the paths 40. Also, the sheet 42 provides an uppersolar energy absorbing surface region 44 which absorbs solar energy andconducts this as heat into the water flowing through the paths 40. Thissheet 40 could be made in different forms. One possibility is to makethe sheet 42 a membrane 42. Also, a solid sheet of laminar plastic,covered by a thin layer of acrylic (for UV stability) could be used. Inaddition, a thinner polystyrene plate could be used below this to form asandwich construction making the sections 28 strong enough so that thepool cover 22 could also be used as a security cover to prevent childrenfrom drowning.

With reference back to FIG. 2, at the left hand side of the drawing ofFIG. 2, there is shown an inlet hose 46 which takes in the water anddirects it into the nearest panel 28. The water flows sequentiallythrough the panels 28 to be heated until it reaches the outlet 32, andat the right end of the FIG. 2, there is shown an outlet hose 48 thatreceives the water and directs the water to a lower elevation in thewater 16. The panels 28 can be connected in a series so that the heatedwater flows from one panel 28 to the next and exits the last panel viaoutlet 34. Alternatively, the water from the pool is fed into all coversections in parallel so that the heated water exits outlets 34 in eachpanel 28. This will be described later in this text with reference toFIGS. 18-21. Thus back pressure in the system can be reduced and thepumping of the water can be accomplished more easily.

As indicated previously in this text, the second main component of thesystem 20 is the power and pumping section 24 that is shown in itsoperating position in FIGS. 1 and 2. To describe the main components ofthis section 24, reference is first made to FIG. 6. In FIG. 6, there areshown the four main components of this section 24, these being thefollowing: a solar power section 50, a battery section 52, a pumpsection 54, and a control section 56.

With regard to the solar power section 50, this is shown not onlyschematically in the drawing of FIG. 6, but also is shown in FIGS. 1 and2. This solar power section 50 comprises a photovoltaic panel whichconverts the solar energy into electrical energy and has a powerconnection to the battery section 52. The battery section 52 comprises astorage battery. The pump section 54 functions (as it's name implies) totake the water 16 from the pool 14 and pump it through the hose 46 totravel through the cover section 22 to be heated by the sunlight thatreaches the cover section 22. In FIG. 2 the pump section 54 is shown asa submersible pump connected by wire 55 to the other components in thepower and pumping section 24. The control section 56 operates to closeand open a switch 70 to cause the pump section 54 to operate or to shutit down, this being done in cycles, with each cycle having a pumpingperiod and a non-pumping period. The manner in which it is accomplishedwill be explained in the following paragraphs.

With the main components of the system 20 having now been described, letus now turn our attention to the mode of operation, after which therewill be a more detailed description of the components and variousfeatures of the embodiments of the invention.

Let us assume that it is a sunny day and a higher level of solar energyis being transmitted to the solar panel section 50, with the result thatthe water which is then present in the cover section 22 warms up morerapidly. In that situation, to obtain optimum heating efficiency it isdesirable that the water which has been heated up to a desiredtemperature should be moved within a reasonable time period from thecover section 22 and delivered back to the pool 10, this beingaccomplished by the pump section 54 pumping a second quantity of waterinto the cover section 22 to be heated and to displace the now heatedwater in the cover section 22. That would mean that the cycles of thepump section 54 being turned on and off should occur with shorter timeintervals between pumping modes.

Now, let us further assume that it is a rather cloudy day where there islower energy level of sunlight making its way to the cover section 22 sothat the water in the cover section 22 heats up more slowly. It is awaste of electrical energy to pump another amount of water into thecover section 22 prematurely to displace the water which had been warmedvery little. Therefore, the time intervals between pumping cycles shouldbe greater. In the present invention, to operate the system in the mostefficient manner, the timing of the pump cycles is automaticallyregulated so that the timing of the cycle intervals matched theintensity of the solar radiation.

To comment further on this mode of operation the control section 56 isoperatively connected at least to said pump section 54 to cause the pumpsection 54 to operate in cycles to first circulate the water through thecover section 22 for a pumping period of the cycle and turn off the pumpsection for a non-pumping period of the cycle. The control section isarranged to be responsive to a value or occurrence related to intensityof the solar energy directed to the cover section 22 and to the powerand pumping section 24, so that during periods of greater intensity ofthe solar energy the non-pumping periods of the pump section 54 are oflesser duration and during periods of lesser intensity of the solarenergy, the non-pumping periods are of greater duration. Thus the system20 is self regulated to take advantage of periods of greater solarintensity when water in the cover section is heated more rapidly, byhaving the pump section operate in more frequent cycles to re-circulatemore heated water, and during periods of lesser solar intensity thecycles are of less frequency.

With further reference to FIG. 6, the solar power section 50 has at aconnecting location 58 a direct connection 59 to the battery at 60, tothe motor at 62 in the pump section 54, and to the control section 56 ata terminal location at 64 labeled as “V_(C)” in FIG. 6. Then theconnecting location 58 of the solar cell 50 also connects to a diode 66to another location 68 on the control section 56, this connection beingindicated at “p” in FIG. 6. Also, the motor 54 connects through anoff/on switch 70 that has a second connection at 72 to the solar powersection 50, and also connects to a second terminal location 74 on thebattery section 52.

The pump section 54 would consume more power than the power which thesolar power section 50 could generate, even on a rather bright sunnyday. For example, the maximum power output of the solar power section 50could be 5 watts and the battery section 50 could consume, for example,20 watts in its normal mode of operation. This ratio obviously could bechanged, and the ratio of the peek power of the solar energy section 50at peak operating periods could be anywhere from 10%, 20%, 30%, 40%,50%, 60%, 70%, or possibly higher. This would depend upon a number offactors to obtain a proper balance among the operating components tooptimize the operation. Therefore, when the battery section 52 is fullycharged and a cycle is starting, the pump section 54 will beginconsuming electricity, so that energy will be drained from the batterysection 52, so that the voltage at the battery terminal 60 will begindropping and will continue to drop during the pumping period. Thus,during the time period when the motor 54 is operating to pump the water,the motor is taking energy not only from the solar power section 50, butit also is taking power from the battery section 52. This will cause thevoltage at the battery terminal at 60 to keep dropping until the batteryvoltage drops to the lower level of, for example, 11 to 11½V. When thishappens, the drop in voltage is detected by the control section 56 atthe location 64 (i.e. the terminal V_(C)), and this causes the controlsection 56 to open the switch at 70 to cause the motor 54 to stopoperating, thus completing the pumping cycle.

When the motor 54 does stop operating, the solar energy which isimparted to the solar power section 50 continues to be delivered torecharge the battery section 52. The solar power section 50 willcontinue to charge the battery section 52 until the voltage reaches apreset level of, for example, 13 to 13.5V, and at this time this isdetected by the control section 56, which starts the motor 54 then whichstarts operating again to start a second pumping cycle.

One of the problems associated with starting up electric motors is thatwhen the motor is just starting to operate, it draws a surge of currentto get the motor started. Then after the motor has reached a certainlevel of RPM's, the back emf (i.e. back electromagnetic force) in themotor reduces the amount of current. Therefore, the battery must besized to have sufficient capacity to meet the higher current demands ofthis surge of power.

To explain the operation of this first embodiment more completely, thereis provided below Table I which illustrates a simple program for themicroprocessor in the control section 56. TABLE I 1 SET voltage at whichpump is started V_(R) (typically 13-13.5 V) 2 SET voltage at which pumpis stopped V_(O) (typically 1 . . . 5-12 V) 3 MEASURE present circuitvoltage V_(C) 4 IF V_(C) ≧ V_(R) THEN open switch 70 ELSE RETURN to line3 5 MEASURE present voltage V_(C) 6 IF V_(C) ≦ V_(O) THEN close switch70 ELSE RETURN to line 5 7 RETURN to line 3

The control section 56 will keep measuring the present voltage V_(C) inthe bottom Section 53 until the charge from the solar power sectionraises V_(C) to the set level V_(R) or above. The pump section 54 willthen start and the control section 56 resumes measurements of V_(C).When the power consumed by the pump section 54 has brought V_(C) to theset level V_(S) or below, the pump section 54 stops. The control sectionwill again measure V_(C) in anticipation of the next run cycle.

The above circuit is simple but in practice, as discussed above, manypump motors draw a high amperage current when they start, so that hereis an abrupt momentary drop in voltage, and this could shut off the pumpas it tries to start. Therefore, a second embodiment of the power andpumping section 54 is shown in FIG. 7. which shows a block diagram of amodified power circuit that circumvents this problem. It uses the samecomponents as the circuit shown in FIG. 6, but inserts another diode 76and a resistor 78 between the solar panel 50 and the battery section 52.A direct input connection 80 between the solar power section 50 and thecontrol section 56 is also added. This modification permits a separatemeasurement of battery voltage V_(B) at input connection 82 to thecontroller and solar panel voltage V_(S) at the input connection 84.Table II illustrates a program for use with this circuit. TABLE II 1 SETbattery voltage limit V_(L) for starting pump (typically 12-13 V) 2 SETsolar panel voltage ΔV for starting pump (typically 0.1 to 0.5 V) 3 Settime x for pump ON (typically 10-60 seconds) 4 Measure battery voltageV_(B) 5 IF V_(B) ≧ V_(L) THEN measure solar panel voltage V_(S) ELSEreturn to line 4 6 IF V_(S) ≧ (V_(B) + ΔV) THEN open switch 70 ELSEreturn to line 4 7 Wait x seconds THEN close switch 70 8 Return to line4

In this case all measurements are made when the pump is off, so that acurrent drop when the pump starts will not affect measurements. Thecontrol section 56 waits until the battery section 52 has beensufficiently replenished to reach voltage V_(L), then checks for thepresence of solar radiation as indicated by a solar panel voltage V_(S)which is higher than the battery voltage by ΔV or more. If this is thecase the pump starts and runs for a preset time “x” and shuts down. Thecontroller then resumes measurements of battery voltage, repeating thecycle when the conditions permit. The time “x” could be varied by thecontrol section in response to the level of the solar energy so thatwhen the solar energy is more intense the time “x” would be longer andwhen the solar energy is less intense times “x” is less.

Using the described cycling mode and circuits achieves three objectives:

(1) Most low-cost commercial 12V pumps are not designed for runningcontinuously. Cycling the pump avoids overheating and extends pump life.Although the water circulates more slowly, this is offset by a longerdwell time in the cover, with a higher water temperature at the exit.

(2) Solar panels are expensive. Cycling the pump permits the use of asolar panel of modest size and cost.

(3) The circuit is self-regulating without the need for additionalsensors. Water is only circulated when there is sufficient solar energyto heat it.

As indicated above, it is obviously possible to use more sophisticatedprogramming, e.g. introducing different voltage thresholds for differentpump run times and/or rest times between cycles. This may help tominimize unnecessary current drain in the circuit, thus maximizing powermanagement. It is equally obvious that there are many possiblevariations in actual circuit design. It may for instance be desirable todesign the circuit so that the pump will not run when it is removed fromthe water, to spare pump life, which can be achieved by measuring theamperage of the pump.

Let us now turn our attention back to the cover section 22 and moreparticularly to the panels 28. It was indicated that the flow paths wereprovided in the form of grooves 40 which were made in the base plate 38,and reference is again made to FIGS. 3, 4 and 5. To elaborate on thisfurther, these grooves 40 are desirably formed in the form of a grid orgrids which could be designed in a variety of different patterns. InFIG. 5, these grooves generally designated by the numeral 40 are shownin the form of two grids. In each grid, there are laterally extendinggrooves 88, and the ends of these grooves 88 are connected at their endportions to rear and forward edge grooves 90 and 91, respectively,extending along the opposite side edges of the panel 28. It will benoted in FIG. 5 that two of the edge openings 41 (i.e. those appearingin the bottom part relative to those showing in FIG. 5) are outwardopenings 41 located further outward toward the ends of the panels 28,while two other on an opposite side which are located at a more centrallocation. Thus, the flow is through the outward openings 41 into therear edge groove 90 which feeds the water into the laterally extendinggrooves 88 to flow forwardly into the forward edge groove 91 to flow tothe central openings 41 to the next forward panel.

The plate 38 of each section is made of a buoyant and insulatingmaterial. An example of a suitable material is a thermoplastic foam withno or low absorption of water. On the upper surface of the plate thereare the previously mentioned cut or molded grooves or paths 40 whichwill form water channels. The grooves 88 and 90 are interconnected toform this grid 32 in a manner which distributes the flow of waterthroughout the entire available area of the cover section 22. It may bedesirable to use several separate grids.

Grids may be designed in many different patterns. Generally there is acompromise between efficient water distribution, ease of emptying thecover when it is pulled out of the pool, and avoiding a large number ofconnections between cover sections. The grids communicate to the outsideof the plate through openings 41, for connecting the inlet and outletmanifolds, and for interconnecting several cover sections. The depthdimension of these grooves 40 could, depending on various factors, havea depth dimension les or greater than the width dimension of the groovesor paths 40 at the top of the grooves, and within the broader scope,could be 90%, 80%, 70%, 60%, 50%, 40%, 30% or 20% of the width dimensionor less or possibly 120%, 140%, 160%, 180%, 200% of said width dimensionor greater.

The aforementioned sheet 42, which seals the upper surface of the grids86 may be made of plastic or rubber film, or of coated or impregnatedfabric, or as a stiff or moderately yielding plate. The sheet 42 isattached to the base plate 38 using adhesives, welding or other suitabletechniques. If the water is to be heated by contact with the sheet 42above, a dark energy absorbing color is chosen for the sheet 42.Alternatively the sheet 42 can be transparent, and in this case thegrooves have the energy collecting surface.

A third embodiment of the present invention is shown in FIGS. 8, 9 and10A-10E. There is a power support section 94 to contain and/or supportcomponents of the solar panel section 50. In the following descriptionthis section 94 will be called simply the “support section 94 ”.

This support section 94 comprises a major support member 96 and anadjustment support member 98. (See FIGS. 8 and 9 ). These two supportmembers 96 and 98 can be connected together in a manner to providesupport for the solar power section 50 in five different angularpositions, beginning with a nearly horizontal 15° position (the 15°angle and the other angles being measured relative to a horizontalaxis), a 30° position, a 45° a position, a 60° position, and possibly a75° position.

The two support members 96 and 98 are in the form of a regular prismhaving a uniform cross sectional configuration along a longitudinalaxis. The cross section of each of these members 96 and 98 is that of aright triangle, with the major support member 96 being in a 90°-60°-30°right triangle, designated the “major triangle”, and the adjustmentsupport member being in a 90°-75°-15° right triangle, designated the“adjustment triangle”. Since the critical functional features of thesetwo support members 96 and 98 are their exterior surfaces, the followingdiscussion will simply refer to their surfaces, with the understandingthat these surfaces are the surfaces of wall or panel members which makethe prismatic configuration of these two support members 96 and 98.

Reference will now be made to FIG. 10A which is drawn to an enlargedscale and shows the two members 96 and 98 somewhat schematically in asectional view (or an end view). In FIG. 10A the two members 96 and 98are placed on top of one another so that the support surface of thesupport surface solar panel would be at a 15° angle with the horizontal.

For purposes of description the sides and angles of the major triangle96 and the adjustment triangle 98 will be given designations where asmall letter of the alphabet will designate either a side or an anglewith a “−1” referring to those of the major triangle 96, and a “−2”referring to the sides or angles of the adjustment triangle 98. Thesedesignations are indicated in FIG. 10A which shows the two supportmembers 96 and 98 stacked one on top of the other.

Below are two tables identifying the angles and sides by theirdesignations and also a brief descriptive designation. Major Triangle 96Angle a-1 primary major support angle Angle b-1 secondary major supportangle Side c-1 primary major support surface Side d-1 major solar panelsupport surface Side e-1 secondary major support surface Angle f-1 thirdmajor angle

Adjustment Triangle 98 Angle a-2 primary adjustment support angle Angleb-2 secondary adjustment support angle Side c-2 first primary adjustmentsupport surface Side d-2 second primary adjustment support surface Sidee-2 third adjustment side Angle f-2 third adjustment angle

The major support member 96 has a primary major support angle a-1 whichis the 30° angle (i.e. about ⅓ of a right angle) where the hypotenused-1 joins the side c-1 of the major right triangle, and the adjustmentsupport member 98 has its primary adjustment support angle a-2 which isthe 15° angle (i.e. about one sixth of a right angle) of the righttriangle. With the angle a-2 being about one half of the angle a-1, thesignificance of these two angles a-1 and a-2 is that in one position,such as shown in FIG. 10A and 10B, to arrive at the slant angle of 15°,the 15° of angle a-2 is subtracted from the 30° of angle a-1 to make thealignment angle of the support surface d-1 of the major support member96 at the 15° slope. As will be shown later herein, with the position ofthe adjustment support member 98 being reversed, so that the 15° anglea-2 is added to the 30° angle a-1 the alignment angle of the supportsurface increases to 45°.

To complete the description of the major support member 96, thehypotenuse surface d-1 is the surface which supports the solar panel inthe proper alignment. The longer leg c-1 is a primary major supportsurface. The short leg of the triangle c-1 is the secondary majorsupport surface and it rests on the underlying surface to provide thesupport surface at a 600 slant (See FIG. 10E). The angle f-1 is a thirdmajor angle, the size of which is dictated by the other angles and sidelengths.

The adjustment support member 98 has first and second primary adjustmentsupport surfaces which are designated c-2 and d-2, respectively. Both ofthese surfaces c-2 and d-2 provide support, and (as indicated before)depending upon which way they are aligned relative to their majorsupport member in the 15° and 45° positions, this will determine whetherthere will be a larger (45°) or smaller (15°) angle of slant. There is asecondary adjustment support angle b-2 which provides more directsupport except in one position that adds stability to the supportsection 94. The side e-2 is a third adjustment side, and angle f-2 is athird adjustment angle, the size of these being dictated by the size andalignment of the other angles and sides of the adjustment triangle.

To discuss now the manner in which the major support member 96 and theadjustment support member 98 may be used to obtain the various angularorientations for the solar panel section, reference shall be made toFIGS. 10B-10E.

FIG. 10B is the same as FIG. 10A, and it shows the arrangement to obtainthe 15° slant from the horizontal. To accomplish this, both the majorand adjustment support members 96 and 98 are utilized, and these arestacked one on top of the other so that the primary major supportsurface c-1 is placed against the first adjustment support surface c-2.The second adjustment support surface d-2 rests on the ground locationand the major solar panel support surface d-1 has the desired slant of15 degrees and supports the solar power section 50. In thisconfiguration, the 15° value of angle a-2 is in effect subtracted fromthe 30° value of the angle a-1 to arrive at the 15% angle of slope. ;

To obtain the 30° orientation of FIG. 10C, only the major support member96 is used. The primary major support surface c-2 rests on the groundsurface or paved surface, and the major solar panel support surface d-1has the solar power section 50 positioned thereon. The angle a-1dictates the 30° tilt angle.

To obtain the 45° angle slope of FIG. 10D, the two support members 96and 98 are positioned so that the two primary support angles (theprimary major support angle a-1 and the primary adjustment support anglea-2) are added to one another to make the 45° angle. It can be seen thatthis is accomplished by having the two surfaces c-1 and c-2 against oneanother with the surface d-2 resting on the ground location. However,this arrangement differs from the arrangement of FIG. 10B in that themembers 96 and 98 are oriented so that the two angles a-1 and a-2 arenext to one another.

To obtain the 60° slant angle of FIG. 10E, the major support member 96and the adjustment support member 98 are arranged so that the secondarymajor support surface e-2 of the member 96 rests on the underlyingground or paved surface, and also the third adjustment side e-2 alsorests on the ground surface, with the two members 96 and 98 being joinedto one another. In this case the secondary major support angle b-1 whichis 60° dictates solely the 60° angle of slant of the major solar panelsupport surface d-1.

To obtain a 750 slope, the same configuration would be used as in FIG.10E, except that the second adjustment surface d-2 would now become asupport surface for the solar power section 50. This would be lesslikely to occur, since such a steep angle would be used only when thesun is very low on the horizon, and in that position the solar energywould likely be substantially less.

In FIG. 8, the support section 94 is shown in its position of FIG. 10D.The solar panel of the solar power section 50 is positioned so as to bewithin the major support section 96, with its solar facing surfaceexposed. Also, the battery section 52, control section 56 are housedwithin a chamber 100 which is formed by the three walls of the majorsupport member 96. The two support members 96 and 98 may be constructedusing buoyant and insulating materials such as thermal plastic foam orwith inflatable parts, so that it will float should the unit beaccidentally dropped into the pool. A handle 99 is provided on thesection 96. Also, the thermally insulating properties of the materialused will also protect the battery and electronics from excessive heat,as the unit sits exposed to the sun.

As can be seen in the view of FIG. 9, the two support members 96 and 98could be connected by Velcro fastener, such as shown at 102. However,other fasteners could be used.

Reference is now made to FIGS. 11-15 to illustrate how the variousconnections can be made between the panels 28, with respect to theconnections by which the water can flow from one panel 28 to the otherand also how these can be physically connected in a manner that thepanels could be folded over one on top of the other.

FIG. 11 shows the basic construction of the fluid joints. A coupling 104has one barbed end that snaps into the openings 41 on the sides of thecover sections and another barbed end on which tubing 106 can bethreaded.

Inlet and outlet hoses are illustrated in FIG. 12. A standardquick-connect hose coupling 35 is installed on the tubing, so that thepump or the optional outflow tubing can be easily connected anddisconnected. On the inlet hose only there may also be a restrictionvalve to ensure that the water is evenly metered into the water channelgrids in the cover sections. The restriction valve 108 additionallyserves to limit the water pressure in the cover to protect itsintegrity.

FIG. 13 shows joining two cover sections, using coupling 104 on bothends of the tubing. An alternative manner of joining panels 28 sectionsis shown in FIG. 14, where a T shaped tubing 110 is used. As thehydrostatic pressure of the water inside cover sections is low, theinverted leg 112 of the T (typically protruding 2 inches/5 cm upwards)serves as a vent to remove trapped air but does not allow the water toescape when the cover lies flat on the pool surface. However, when thecover is retrieved, tilting the cover sections, these vents allow thewater to rapidly drain out of the cover.

To avoid putting too much stress on the fluid joints the cover sectionsare also mechanically joined using flexible sheets or straps, which maybe a continuation of the sheet cover 42 covering the panels 28. FIG. 15shows an example where two overlapping sheets 42 which are joined usingVelcro fasteners 84. Other attachment systems using snaps, hooks,zippers or similar means are equally possible.

Material used for constructing fluid and mechanical joints are selectedfor their ability to easily bend and/or fold and to tolerate repeatedsuch actions. Elasticity and an intrinsic tendency to return to theoriginal shape are also important. In fluid tubing it is essential toavoid that permanent creases or knees are formed, as these could blockthe fluid flow. Examples of suitable tubing materials are siliconerubber, EPDM-rubber, Tygon, and Viton which are commercially available.The elastic spring action of fluid and/or mechanical joints is alsouseful as an aid in making the cover spread out when it is deployed onthe water.

Mechanical attachment systems using Velcro or snaps may also be usefulto attach various accessories to the cover. One useful accessory is apassive cover section, with insulation but without water channels, as itcan be cut to adapt the shape and dimensions of the cover to fitdifferent kinds of pools. Other accessories include anchor points tosecure the cover, and/or tracks to guide the deployment and retrieval.Also, such accessories could be a docking station to facilitatelaunching and retrieval of the cover and brackets to enable the cover tofunction as a security device to prevent children from falling into thepool.

A common feature of all of the described joint types is that they do notrequire sophisticated tools or adhesives. This allows the end user toassemble the pool heater system him/herself using the elements suppliedand to tailor the installation to fit individual needs. The system canstart out small and later be expanded to cover a larger surface or theentire pool. The modular approach also allows cost savings intransportation and warehousing, as only a limit number of standardelements of modest size are required for a wide variety of installation.

In the normal mode of operation of the embodiments of the invention,since the entire operation is automatic the cover section 22 remains onthe pool, there is no need for any human intervention. During the dayswith little sun, no water is circulated through the cover. Theinsulating properties of the cover minimize heat loss. When solar energyis available, it is harnessed by the automatic circulating of the waterso that it can be heated at the surface of the cover.

To illustrate how the cover section 22 could be retrieved from itsoperating position on the pool and later positioned on the pool,reference is made to FIGS. 16 and 17. These illustrate the handling ofthe cover section 22.

To remove the cover section 22 from the pool, the power and pumpingsection 24 is disconnected by means of a quick connect coupling 35. Thefirst panel 28 is pulled up using a strap 31. By pulling further on thisstrap 31, the following panel 28 is folded over the first. The followingpanels 2 are pulled up in the same manner, again using the strap 31provided The cover section 22 can be stored as a stack of folded panels28, as shown in FIG. 17. In the illustration, the support section 94 isshown placed on top of the stack with the pump section 54 tucked insideits storage compartment.

To deploy the system 20, the removal procedure is reversed. The outlettube, if used, is reconnected. The uppermost panel 28 is then tiltedinto the pool 10, followed by subsequent panels 28. The spring action ofthe elastic fluid and/or mechanical joints between the section 22 aid inthe deployment as they force the cover to flatten and float out into thepool 10, as the curved arrows in FIG. 16 attempt to illustrate. Finallythe power and pumping section 24 is reconnected to the cover.

A fourth embodiment of the present invention will now be described withreference to FIGS. 18, 19, 20 and 21. Earlier in this text, the firstembodiment is described as having the flow paths between the panels 28being in series, and it was then stated that there could be analternative flow system where the flow of the water through the panelsis done in a manner which could be described as a parallel flow pattern.This is accomplished in this fourth embodiment. In describing thisfourth embodiment, components which are the same as, or similar to,components of the earlier embodiment will be given like designationswith an “a” suffix distinguishing those of the first embodiment.

To describe this in general terms, in this fourth embodiment, the flowof the water is directed into each panel 28 a and is discharged fromeach panel directly into the pond. In FIG. 18, there is shown in planview one of the panels 28 a which is used in this fourth embodiment.

For purposes of explanation, this panel 28 a is shown with only a smallpart of the top cover sheet 42 a, (See the sectional view of FIG. 19),with the understanding that the cover sheet 42 a would be bonded to theentire upper surface of the panel 28 a.

The panel 28 a comprises a base plate 38 a, having the flow paths 40 aformed as grooves in the plate 38 a. As in the first embodiment, theseflow paths comprise the laterally extending grooves 88 a, and also theedge grooves in which describing this fourth embodiment will beconsidered as a rear edge groove 90 a and forward edge groove 91 a.These grooves 88 a, 90 a and 91 a are formed in two grids 89 a. Thepanel 28 a has an end to end axis 116 a and a rear to front axis 118 a.

The base plate 38 a differs from the base plate 38 of the firstembodiment in that the in addition to the grooves 88 a, 90 a and 91 a,there are two laterally extending grooves 120 a in which is positioned amain central feed conduit 122 a at the center of its grid 89. Eachconduit 122 a has a rear inlet 124 a and a forward outlet 126 a. Therear 124 a of each main feed conduit 122 a has a upwardly facingmetering opening 128 a in the form of a slot, or some otherconfiguration or design. Also, there are two oppositely positioned rightangle connecting slots 129 a to connect to a pump hose or the like. (SeeFIG. 20).

At the forward end 126 a of the conduit 122 a, there is a front endconnection, indicated schematically at 130 a, and this could connect toany one of the fluid conduit arrangements which are shown in FIGS.11-14.

At opposite forward locations of each of the two grids 89 on the baseplate 38 a there are two outlet openings 132 a which open from the outerends of the forward edge groove 91 a downwardly directly into the pool.There is positioned in each of these openings 132 a outlet flow controltube 134 a (See FIG. 21). This tube 134 a has a vertically aligned flowthrough passageway 135 a, and the upper inlet edge 136 a which extends180° around the upper end of the tube 134 a and is located a shortdistance below the water level of the flow in the grooves 88 a, 90 a,and 91 a. This 180° edge of the outlet flow control tube 134 a is at alevel so that the warmer water which collects at the upper surface ofthe water in the grooves 88 a, 90 a and 91 a will flow over the edge 136a so that the additional water then flows in will be able to be incloser heat exchange relationship with the top sheet 42 a of the panel28 a.

At the corner portions of the panel 28 a, there are recesses orconnecting grooves 138 a in which can be placed rubber straps,connecting plates, or other fastening devices so that connection can bemade to adjacent panels 28 a.

To describe the operation of this fourth embodiment, let it be assumedthat this panel 28 a is the panel which receives the primary flow ofwater directly from the pump section 54. This water flows into the rearinlet 124 a of each of the main feed conduits 122 a. A portion of thiswater will immediately flow through the upwardly facing metering opening128 a to flow into the rear edge groove 90 a. The water flowing into theedge groove 90 a flows in opposite directions toward the ends of thegroove 90 a, and as it does so, the water flows into the rear entryportions of the laterally extending grooves 88 a. The water flowing in aforward direction through the grooves 88 a enters into the forward edgegroove 91 a and then flows laterally toward the outlet openings 132 a toflow over the 180° edge 136 a of the flow control tube 134 a anddownwardly through the tube 134 a into the pool.

At the same time, the main stream of water from the pump section 54continues its flow through the main feed conduit 122 a through the frontconnection 130 a to the rear inlet end 124 a of the adjacent panel 28 a.Then the same flow pattern occurs in the next adjacent panel 28 a, withthe water flowing into the rear edge groove 90 a, through the grooves 88a and into the forward edge groove 91 a. This flow pattern continues,until that water flows into the panel 28 a which is the end panel in thefurthest downstream direction, and in that panel 28 a, the forward endof the main central feed conduit 122 a is plugged.

Thus, in this flow pattern, the central feed conduit 122 a has asufficiently large cross section and also has a low friction innersurface so that there is a relatively small back pressure along thelength of the main central feed conduit 122 a. Further, the meteringopenings 128 a can be sized so that the amounts of flow through each ofthe panels 28 a is substantially equal.

1. A self regulating heating system to heat water in a pool, having apool location: a) cover section constructed and arranged to bepositioned at an upper surface of said water and to extend over at leasta portion of said surface of the water; b) said cover section having asolar energy absorbing surface region and having flow paths with inletand outlet portions for water to pass through said cover section in amanner to be heated by energy absorbed by said solar energy absorbingsurface region; c) a power and pumping section to circulate water fromsaid pool through said cover section to be heated and back to said pool;d) said power and pumping section comprising a pump section to pump thewater, a battery section to supply power to the pump section, a solarpower section also exposed to solar energy to convert said solar energyfor the power and pumping section to enable the pump section to operate,and a control section; e) said control section being operativelyconnected at least to said pump section to cause the pump section tooperate in cycles to first circulate the water through the cover sectionfor a pumping period of the cycle and turn off the pump section for anon-pumping period of the cycle, said control section being arranged tobe responsive to a value related to intensity of the solar energydirected to the cover section and the power and pumping section, so thatduring periods of greater intensity of the solar energy the non-pumpingperiods of the pump section are of lesser duration, and during periodsof lesser intensity of the solar energy, the non-pumping periods are ofgreater duration; whereby the system is self regulated to take advantageof periods of greater solar intensity when water in the cover section isheated more rapidly, by having the pump section operate in more frequentcycles to re-circulate more heated water, and during periods of lessersolar intensity the cycles are of less frequency.
 2. The system asrecited in claim 1, wherein during the non-pumping period of the cycle,electrical energy from the solar power section charges the battery up toa higher level and said control section responds at least in part to asituation where the voltage level of the battery section rises to ahigher level to start the pumping period of the cycle.
 3. The system asrecited in claim 2, wherein said system is characterized in that duringthe pumping period of the cycle the power consumed by the pump sectioncauses the output voltage of the battery section to drop, said controlsection being arranged to respond to a voltage drop in the batterysection to end the pumping period of the cycle.
 4. The system as recitedin claim 1, wherein said system is characterized in that during thepumping period of the cycle the power consumed by the pump sectioncauses the output voltage of the battery section to drop, said controlsection being arranged to respond to a voltage drop in the batterysection to end the pumping period of the cycle.
 5. The system as recitedin claim 1, wherein the pumping period of at least some of the cycles isterminated in response to the length of time from the starting of thepumping cycle.
 6. The system as recited in claim 5, where the length oftime from the starting of the pumping cycle would at least some of thetime be greater at a higher level of solar intensity and lower for alower level of solar intensity.
 7. The system as recited in claim 1,wherein said solar power section has a power connection to said batteryand to said motor, so that during the pumping period of the cycle, thesolar power section is transmitting power to said pump section, and saidbattery section is also transmitting power to said pump section, withthe pump section drawing sufficient power so that the solar powersection and the battery section supply power to the pump section, butwith the output voltage from the battery section becoming lower duringthe pumping period of the cycle, said control section having amonitoring function to be responsive to the level of the output voltageof the battery section to cause the pump section to start pumping toinitiate the pumping period when the output voltage of the battery hasreached a predetermined higher level, and to cause the pumping period ofthe cycle to cease when the output voltage of the battery has reached apredetermined lower level and/or after the predetermined length of timefrom a starting of the pumping cycle.
 8. The system as recited in claim1, wherein said solar power section has a power connection to saidbattery section and to said pump section, said control unit having amonitoring connection to a voltage output of said battery section and toa voltage output of said solar power section, said control section beingarranged to monitor the voltage of the solar power section relative tothe voltage output of said battery section to enable said battery to becharged to a predetermined higher level prior to starting the pumpsection for the pumping period of the cycle until the battery sectionhas been charged to a level to supply sufficient power to start the pumpsection operating during the beginning of the pumping period.
 9. Thesystem as recited in claim 8, where the length of time from the startingof the pumping cycle would at least some of the time be greater at ahigher level of solar intensity and lower for a lower level of solarintensity.
 10. The system as recited in claim 1, wherein said coversection comprises a plurality of panels which are arranged to bepositioned in side by side relationship on the water surface, each ofsaid panels being provided with flow paths, and with adjacent panelshaving fluid connections therebetween, said system being arranged sothat the power and pumping section circulates water from the pool intoat least one of said panels and through fluid connections to otherpanels, with the outlet being at one of said other panels, said panelsbeing interconnected with one another so that said panels can be foldedover relative to one another to be stacked one on top of the other. 11.The system as recited in claim 1, wherein adjacent pairs of panels arearranged with connecting straps which extend across the adjacent pair ofpanels, said connecting strips being arranged so that pulling on thestrap lifts opposite sides of the panels upwardly and toward one anotherso that the panels moved to a position being adjacent to one another andare able to be placed in stacked relationship.
 12. The system as recitedin claim 1, wherein said cover section comprises: a) a plurality ofpanels which are arranged to be positioned on the water surface, each ofsaid panels comprising forward and rear side edges, and end edges, saidpanels being positioned in side by side relationship with pairs ofadjacent panels having front and side panels edges of adjacent twopanels in side by side relationship, each panel having a front to rearaxis and an end to end axis perpendicular to the front to rear axis; b)each panel comprising a main feed conduit generally aligned with saidforward to rear axis of the panel and having a rear inlet portion and aforward outlet portion; c) each panel having a rear flow path and aforward flow path, both of which are generally aligned with the end toend axis, and further having a plurality of lateral flow paths spacedfrom one another and extending from the rear flow path to the forwardflow path; d) said rear portion of said main feed conduit having ametering opening to deliver water into said rear flow path at a firstupstream end location relative to said end to end axis to flow along thelength of said rear flow path, with the water in the rear flow pathflowing forwardly through said lateral flow paths into the forward flowpath; e) each panel having a forward water outlet opening which isspaced a substantial distance from the first end to end locationrelative to said end to end axis, to discharge from the panel the waterwhich has flowed through the lateral flow paths and the forward flowpath; f) each panel that has an adjacent forward panel having a fluidconnection of the main feed conduit from its forward outlet portion tothe rear inlet portion of the adjacent forward panel to direct water tothe main feed conduit for distribution through the flow paths of theadjacent forward panel and discharge the water from the adjacent panel.13. The system as recited in claim 1, wherein there is a support sectionfor said solar power section, comprising: a) a major support membercomprising; i. a major solar panel support surface to support said solarpower section in a solar energy receiving position of greater and lesserslant angles; ii. a primary major support surface; iii. said major solarpanel support surface and said primary major support surface slantingtoward one another at a primary major support angle that isapproximately one third of a right angle; b) an adjustment supportmember comprising: i. a first primary adjustment support surface; ii. asecond primary adjustment support surface; iii. said first primaryadjustment support surface and said secondary primary adjustment supportsurface slanting toward one another at a primary adjustment supportangle which about one half of the primary major support angle; c) saidmajor support member being arranged to be positioned on said adjustmentsupport member in a first stacked configuration where the primaryadjustment support angle and primary major support angle are adjacent toone another to position the major solar panel support surface at agreater slant angle substantially equal to the sum of the primary majorsupport angle and the primary adjustment support angle and in a secondstacked configuration the primary adjustment support angle and primarymajor support angle are positioned at opposite sides of the stackedconfiguration to position the major solar panel support surface at alesser slant angle substantially equal to the difference of the primarymajor support angle and the primary adjustment support angle and in asecond stacked configuration.
 14. The system as recited in claim 13,wherein said major triangle also comprises a secondary major supportsurface which makes a third angle with said primary major supportsurface, and said major support member may be positioned with saidsecondary major support surface supporting the major support sectionwith the slant angle of the primary major support surface being greaterthan the sum of the primary major support angle and the primaryadjustment support angle.
 15. A self regulating method of heating thewater in a pool, having a pool location, said method comprising: a)positioning a cover section at an upper surface of the water in the poolto extend over at least a portion of said surface of the water; b)providing said cover section with a solar energy absorbing surfaceregion and flow paths with inlet and outlet portions for water to passthrough said cover section in a manner to be heated by energy absorbedby said solar energy absorbing surface region; c) operating a power andpumping section to circulate water from said pool through said coversection to be heated and back to said pool with said power and pumpingsection comprising a pump section to pump the water, a battery sectionto supply power to the pump section, a solar power section also exposedto solar energy to convert said solar energy for the power and pumpingsection to enable the pump to operate, and a control section; d)providing control inputs at least to said pump section to cause the pumpsection to operate in cycles to first circulate the water through thecover section for a pumping period of the cycle and turn off the pumpsection for a non-pumping period of the cycle, relating said controlinputs to a value related to intensity of the solar energy directed tothe cover section and the power and pumping section, so that duringperiods of greater intensity of the solar energy the non-pumping periodsof the pump section are of lesser duration, and during periods of lesserintensity of the solar energy, the non-pumping periods are of greaterduration; whereby the system is self regulated to take advantage ofperiods of greater solar intensity when water in the cover section isheated more rapidly, by having the pump section operate in more frequentcycles to re-circulate more heated water, and during periods of lessersolar intensity the cycles are of less frequency.
 16. The method asrecited in claim 15, wherein during the non-pumping period of the cycle,electrical energy from the solar power section charges the battery up toa higher level and said control section responds at least in part to asituation where the voltage level of the battery section rises to ahigher level to start the pumping period of the cycle.
 17. The method asrecited in claim 15, wherein said solar power section has a powerconnection to said battery and to said motor, so that during the pumpingperiod of the cycle, the solar power section is transmitting power tosaid pump section, and said battery section is also transmitting powerto said pump section, with the pump section drawing sufficient power sothat the solar power section and the battery section supply power to thepump section, but with the output voltage from the battery sectionbecoming lower during the pumping period of the cycle, said controlsection having a monitoring function to be responsive to the level ofthe output voltage of the battery section to cause the pump section tostart pumping to initiate the pumping period when the output voltage ofthe battery has reached a predetermined higher level, and to cause thepumping period of the cycle to cease when the output voltage of thebattery has reached a predetermined lower level and/or afterpredetermined the length of time from the starting of the pumping cycle.18. The method as recited in claim 15, wherein said solar power sectionhas a power connection to said battery section and to said pump section,said control unit having a monitoring connection to a voltage output ofsaid battery section and to a voltage output of said solar powersection, said control section being arranged to monitor the voltage ofthe solar power section relative to the voltage output of said batterysection to enable said battery to be charged to a predetermined higherlevel prior to starting the pump section for the pumping period of thecycle until the battery section has been charged to a level to supplysufficient power to start the pump section operating during thebeginning of the pumping period.
 19. The method as recited in claim 18,where the length of time from the starting of the pumping cycle would atleast some of the time be greater at a higher level of solar intensityand lower for a lower level of solar intensity.
 20. The method asrecited in claim 15, comprising providing said cover section as aplurality of panels, arranging the panels in side by side relationshipon the water surface, each of said panels being provided with flowpaths, and with adjacent panels having fluid connections therebetween,said method further comprising operating the power and pumping sectionto circulate water from the pool into at least one of said panels andthrough fluid connections to other panels, with the outlet being at oneof said other panels, and/or at some of the panels, and interconnectingsaid panels being interconnected with one another so that said panelscan be folded over relative to one another to be stacked one on top ofthe other.